Sema: Adjust result builder operation lookup for MemberImportVisibility.

To avoid spurious diagnostics about unavailable operations when checking uses
of functions that take result builder closures, lookup of result builder
operations needs to ignore the restrictions of the `MemberImportVisibility`
feature. The result builder transform should simply use the operations that are
found and allow later checks to diagnose the use of inaccessible builder
operations.

Resolves rdar://144100445.

Author: tshortli

lib/Sema/BuilderTransform.cpp

@@ -1326,7 +1326,8 @@ ResultBuilderOpSupport TypeChecker::checkBuilderOpSupport(
   dc->lookupQualified(
       builderType, DeclNameRef(fnName),
       builderType->getAnyNominal()->getLoc(),
-      NL_QualifiedDefault | NL_ProtocolMembers, foundDecls);
+      NL_QualifiedDefault | NL_ProtocolMembers | NL_IgnoreMissingImports,
+      foundDecls);
   for (auto decl : foundDecls) {
     if (auto func = dyn_cast<FuncDecl>(decl)) {
       // Function must be static.

test/Constraints/result_builder_member_import_visibility.swift

@@ -0,0 +1,98 @@
+// RUN: %empty-directory(%t)
+// RUN: split-file %s %t
+// RUN: %target-swift-frontend -emit-module -emit-module-path %t/Transitive.swiftmodule -parse-as-library %t/Transitive.swift
+// RUN: %target-swift-frontend -emit-module -emit-module-path %t/Direct.swiftmodule -I %t/ -parse-as-library %t/Direct.swift
+// RUN: %target-swift-frontend -typecheck -verify -I %t/ %t/Client.swift -verify-additional-prefix no-member-import-
+// RUN: %target-swift-frontend -typecheck -verify -I %t/ %t/Client.swift -enable-upcoming-feature MemberImportVisibility -verify-additional-prefix member-import-
+
+// REQUIRES: swift_feature_MemberImportVisibility
+
+//--- Transitive.swift
+
+@resultBuilder
+public struct TransitiveIntBuilder {
+  public static func buildBlock(_ v: Int) -> Int {
+    return v
+  }
+}
+
+public func transitiveTakesTransitiveBuilder(
+  @TransitiveIntBuilder builder: () -> Int
+) {
+  _ = builder()
+}
+
+extension Int {
+  public static func transitiveTakesTransitiveBuilder(
+    @TransitiveIntBuilder builder: () -> Int
+  ) {
+    _ = builder()
+  }
+
+  public static func ambiguous(
+    @TransitiveIntBuilder transitiveBuilder builder: () -> Int
+  ) {
+    _ = builder()
+  }
+}
+
+//--- Direct.swift
+
+import Transitive
+
+@resultBuilder
+public struct DirectIntBuilder {
+  public static func buildBlock(_ v: Int) -> Int {
+    return v
+  }
+}
+
+public func directTakesDirectBuilder(
+  @DirectIntBuilder builder: () -> Int
+) {
+  _ = builder()
+}
+
+public func directTakesTransitiveBuilder(
+  @TransitiveIntBuilder builder: () -> Int
+) {
+  _ = builder()
+}
+
+extension Int {
+  public static func directTakesDirectBuilder(
+    @DirectIntBuilder builder: () -> Int
+  ) {
+    _ = builder()
+  }
+
+  public static func directTakesTransitiveBuilder(
+    @TransitiveIntBuilder builder: () -> Int
+  ) {
+    _ = builder()
+  }
+
+  public static func ambiguous(
+    @DirectIntBuilder directBuilder builder: () -> Int
+  ) {
+    _ = builder()
+  }
+}
+
+//--- Client.swift
+
+import Direct
+
+// expected-member-import-note@-1 4 {{add import of module 'Transitive'}}
+
+transitiveTakesTransitiveBuilder { 1 } // expected-error {{cannot find 'transitiveTakesTransitiveBuilder' in scope}}
+directTakesDirectBuilder { 1 }
+directTakesTransitiveBuilder { 1 } // expected-member-import-error {{static method 'buildBlock' is not available due to missing import of defining module 'Transitive'}}
+
+Int.transitiveTakesTransitiveBuilder { 1 } // expected-member-import-error {{static method 'transitiveTakesTransitiveBuilder(builder:)' is not available due to missing import of defining module 'Transitive'}}
+// expected-member-import-error@-1 {{static method 'buildBlock' is not available due to missing import of defining module 'Transitive'}}
+Int.directTakesDirectBuilder { 1 }
+Int.directTakesTransitiveBuilder { 1 } // expected-member-import-error {{static method 'buildBlock' is not available due to missing import of defining module 'Transitive'}}
+Int.ambiguous { 1 } // expected-no-member-import-error {{ambiguous use of 'ambiguous'}}
+// expected-no-member-import-note@-1 {{use an explicit argument label instead of a trailing closure to call 'ambiguous(transitiveBuilder:)'}}
+// expected-no-member-import-note@-2 {{use an explicit argument label instead of a trailing closure to call 'ambiguous(directBuilder:)'}}